I feel very excited for first time I post in this site. From my boyhood
I like a girl and i love her but she does not respond. Now what
can I do?

There are many things you can do get a girl respond positively, though depends on the girl anyway. Generally you can do some or all of the below things:
-Find out why she hasn't respond and starts from there
-Dress well and decently
-Compliment her, but don't over do it (very important)
-Respect her. Girls hate it when you don't respect them and its a MAJOR turn off
-Take it slow and Find out what she's interested in
-Really, just be yourself, don't brag, girls hate that, you don't make her think you're self-fish, because they know what self-fish guy normally want.